Diaphragm actuator construction



WW D. E. GRISWOLD 3,336,843

DIAPHRAGM ACTUATOR CONSTRUCTION Original Filed Feb. 12} 1964 UnitedStates Patent @fltice 3,336,843 Patented Aug. 22, 1967 3,336,843DIAPHRAGM ACTUATOR CONSTRUCTION David E. Griswold, Costa Mesa, Calif.,assignor to Griswold Controls, Santa Ana, Calif., a corporation ofCalifornia Continuation of application Ser. No. 344,449, Feb. 12,

1964. This application Apr. 11, 1966, Ser. No. 541,582 6 Claims. (Cl.92-100) ABSTRACT OF THE DISCLOSURE A diaphragm mounting for valves andthe like. The peripheral portion of a flexible diaphragm is mountedbetween a pair of rigid elements, one of which includes a groove andlip. The peripheral portion of the diaphragm is adjacent to the lip, andan elastomeric ring is caused by the other rigid element to exert asealing and clamping force against the diaphragm, the peripheral portionof which is deflected axially and offset into the groove by the ring,and the ring forms a sealagainst the lip to isolate the peripheral edgeof the diaphragm.

This application is a continuation of my copending application Ser. No.344,449, filed Feb. 12, 1964 now abandoned.

This invention relates to pressure-operated valves and is particularlyconcerned with an improved mounting for securing a periphery of anannular flexible diaphragm to the movable closure member of the valve.The other periphery of the annular flexible diaphragm is clamped betweenparts of the valve body.

It is the principal object of this invention to provide a new sealingconnection for the peripheral edge of an annular flexible diaphragm.

Another object is to provide a diaphragm mounting which permits the useof a diaphragm cut from sheet stock and does not require custom moldingof the diaphragm. Another object is to provide a positive seal for thecenter hole cut edge of the diaphragm in order to prevent exposure ofthe cut edge to fluid pressure in the valve system. Another object is toprovide a diaphragm mounting wherein the flexible diaphragm material isclamped between positive stops and yet has a controlled clamping force.

Another object is to provide a diaphragm mounting which serves to lock aperipheral edge of the diaphragm to an adjacent metallic member in sucha manner that the parts do not work loose after a period of service.Another object is to provide a diaphragm clamping construction whichpermits the use of a range of resilient stock thicknesses for thediaphragm without changing the dimensions of the metal clamping parts.Another ob ject is to provide a diaphragm mounting in which the clampingparts are of minimum diameter in order to achieve maximum effective areaof the flexible diaphragm.

Other and more detailed objects and advantages will appear hereinafter.

In the drawings:

FIGURE 1 is a sectional side elevation showing construction of apressure-actuated valve having an annular flexible diaphragm connectingthe valve body to the movable closure member.

FIGURE 2 is a fragmentary sectional elevation showing certain of theparts illustrated in FIGURE 1 and illustrating the initial position ofthe parts prior to clamping of the diaphragm.

FIGURE 3 is a view similar to FIGURE 2, showing the parts in clampedposition.

FIGURE 4 is a view similar to FIGURE 2, showing the parts in initialposition illustrating the use of diaphragm sheet stock of greaterthickness.

FIGURE 5 is a view similar to FIGURE 4, showing the parts in clampedposition.

Referring to the drawings, the valve body 10 which is of the globe orangle pattern is provided with a cover 11, secured in place by threadedfastenings 12. The body 10 has a divider wall 13 positioned between theinlet chamber 14 and the outlet chamber 15. A seat member 16 is securedby threads 17 to the divider wall 13, and this seat has a seatingsurface 18 adapted to be contacted by the sealing disk 19 carried on themovable valve closure generally designated 20. A stem 21 is fixed to acentral boss 22 on the valve seat 16 and projects axially through acylindrical guide surface 23 provided on the disk guide 24, therebyserving to guide the movable valve closure 20 toward and away from theseat surface 18. When the parts are in the position shown in FIGURE 1,the valve is closed. When the movable closure member 20 moves axiallyaway from the seat 16, flow of fluid occurs from the inlet chamber 14-through the interior of the valve seat 16 and into the outlet chamber15.

The body 10 and cover 11 have annular confronting faces 25 and 26 whichclamp the outer peripheral edgeof a flexible resilient diaphragm 27. Inaccordance with this invention, the inner peripheral edge of the annulardiaphragm 27 is clamped to the movable closure member 20 by means of anelastomeric O-ring 28 and an annular groove 29. The groove 29 isprovided on the disk retainer 30 on the upper surface thereof and nearits inner diameter. The upstanding annular lip 31 on the disk retainer30 forms the inner boundary of the groove 29. The upper end of the lip31 is rounded, as shown at 32 and 33. The axial distance from the bottomof the groove 29 to the top of the lip 31 is substantially less than thecombined axial thickness of the diaphragm 27 and the O-ring 28.Accordingly, when the parts are moved from the position shown in FIGURE2 to the position shown in FIGURE 3, the upper end of the lip 31 isbrought into metal-to-metal contact with the under surface of thefollower plate 35. This clamping action is accomplished by turning thedisk guide 24 with respect to the thimble 36 along the threads 34. Thereaction forces between lip 31 and plate 35 place a tension force onthimble 36. A shoulder 37 on the thimble engages the upper surface ofthe follower plate 35. The O-ring 28'distorts under the axial clampingload and forces the inner peripheral portion of the flexible diaphragm27 to seat in offset position within the groove 29. The rounded corners32 and 38 prevent cutting of the O-ring 28 or the flexible diaphragm 27.A seal ring 40 prevents leakage between the thimble 36 and the diskretainer 30.

FIGURES 4 and 5 show how the same metallic parts 30, 35, and 36 may beemployed to clamp a diaphragm of greater thickness. The metal parts arethe same as previously described, but the diaphragm 27a is thicker thanthe diaphragm 27. Accordingly, an O-ring 28a is selected which iscorrespondingly thinner in cross-section than the O-ring 28, so that thetotal initial thickness of the flexible diaphragm and O-ring aresubstantially the same as before. FIGURE 4 shows the position of theparts before applying axial clamping force to the diaphragm 27a andO-ring 28a. FIGURE 5 shows the position of the parts after the clampingforce is applied by means of the threads 36 between the disk guide 24and thimble 36. The O-ring 28a distorts and forces the inner peripheryof the diaphragm 27w into the groove 29.

The small arrows in FIGURES 3 and 5 of the drawings illustrate thecompression forces which are applied by the distorted O-ring against thediaphragm and against the metal parts.

From the foregoing description, it will be understood that the flexiblediaphragm which is cut from sheet stock is positively sealed at itsinner periphery in a manner so that its out edge 41 is not exposed tofluid pressures in the valve system. The metal-to-metal contact betweenthe lip 31 and the underside of the follower plate 35 provides apositive stop, yet controls the clamping force applied to the flexiblediaphragm. Moreover, the clamping area of the diaphragm is kept to aminimum adjacent the inner periphery thereof, so that the major portionof the surface of the diaphragm is responsive to fluid pressures onopposite sides thereof.

A control pipe 43, threaded into the cover 11, is connected to a valve,not shown, for controlling admission and escape of fluid from thechamber 44 by way of the port 45. Pressure in the valve outlet chamber15 acts on the undersurface of the flexible diaphragm 27, and pressurein the chamber 44 acts on the upper surface of the diaphragm. The valvespring 49 acts in a direction to hold the disk 19 against the seatsurface 18. An adjustable stop 46 is connected to the cover 11 bythreads 47. Manual turning of the handle 48 causes the stop 46 to bepositioned at the desired height to engage the upper end of the thimble36 to limit opening movement of the movable valve member 20.

Having fully described my invention, it is to be understood that I amnot to be limited tothe details herein set forth, but that my inventionis of the full scope of the appended claims.

I claim:

1. An annular flexible diaphragm having a peripheral portion and amounting for the said peripheral portion of said annular flexiblediaphragm, said mounting comprising: a pair of axially spaced rigidelements, one of the elements having an axially extending lip and anannular groove adjacent said lip, an elastomeric ring, the peripheralportion of the flexible diaphragm being adjacent to said lip and beingpositioned between the groove and said ring, and clamping means actingagainst said elements for deflecting the peripheral portion of thediaphragm axially and offset into said groove by distortion of the ringunder force of said clamping means, said distorted ring forming a sealagainst said lip and also exerting a sealing and clamping force throughthe diaphragm and against the opposing elements to thereby isolate theperipheral portion of said flexible diaphragm in said groove fromexternal fluid pressures.

2. The combination set forth in claim 1 in which said lip isreceived bythe inner peripheral portion of said flexible diaphragm.

3. The combination set forth in claim 2 in which the mounting is movablein an axial direction as said annular flexible diaphragm is flexed.

4. An annular flexible diaphragm having a peripheral portion and amounting for the peripheral portion of said annular flexible diaphragm,said mounting comprising: a pair of axially spaced rigid elements, saidelements having radially extending confronting faces receiving a portionof the flexible diaphragm therebetween, one of said elements having anaxially extending lip on its periphery extending above the face on saidelement, the said one element having an annular groove adjacent said lipand extending below said face on said element, the groove having abottom surface parallel to said face, a convex shoulder on said elementjoining the bottom of said groove to said face, an elastomeric O-ring,the peripheral portion of the flexible diaphragm being adjacent to saidlip and being positioned between the groove and said O-ring, andclamping means acting against said elements for deflecting theperipheral portion of the diaphragm axially and around said convexshoulder and offset into said groove by distortion of the O-ring underforce of said clamping means, said lip on one of said elements engagingthe other element to limit the compression force applied by said O-ringto the diaphragm, said distorted O-ring forming a seal against said lipand also exerting a sealing and clamping force through the diaphragm andagainst the opposing elements to thereby isolate the peripheral portionof said flexible diaphragm in said groove from external fluid pressures.

5. The combination set forth in claim 4 in which said lip is received bythe inner peripheral portion of said flexible diaphragm.

6. The combination set forth in claim 5 in which the mounting is movablein an axial direction as said an nular flexible diaphragm is flexed.

References Cited UNITED STATES PATENTS 116,669 7/1871 Blake 92-102389,099 9/1888 Newman 251-61 X 2,678,663 5/1954 Chyba 92-102 2,786,4233/1957 Coffey 103-150 3,101,191 8/1963 Wolfensperger 92-102 X MARTIN P.SCHWADRON, Primary Examiner.

I. C. COHEN, Assistant Examiner.

1. AN ANNULAR FLEXIBLE DIAPHRAGM HAVING A PERIPHERAL PORTION AND AMOUNTING FOR THE SAID PERIPHERAL PORTION OF SAID ANNULAR FLEXIBLEDIAPHRAGM, SAID MOUNTING COMPRISING: A PAIR OF AXIALLY SPACED RIGIDELEMENTS, ONE OF THE ELEMENTS HAVING AN AXIALLY EXTENDING LIP AND ANANNULAR GROOVE ADJACENT SAID LIP, AN ELASTOMERIC RING, THE PERIPHERALPORTION OF THE FLEXIBLE DIAPHGRAM BEING ADJACENT TO SAID LIP AND BEINGPOSITIONED BETWEEN THE GROOVE AND SAID RING, AND CLAMPING MEANS ACTINGAGAINST SAID ELEMENTS FOR DEFLECTING THE PERIPHERAL PORTION OF THEDIAPHRAGM AXIALLY AND OFFSET INTO SAID GROOVE BY DISTORTION OF THE RINGUNDER FORCE OF SAID CLAMPING MEANS, SAID DISTORTED